1. Field of the Invention
There are two main classifications of assays for the purpose of detecting and quantifying the presence of a molecule or type of molecule within an sample, namely, a heterogenous assay and a homogeneous assay.
The heterogeneous assay requires separation, either by washing or other physical means, of the reaction elements between the individual steps of the assay procedure. During an assay normally, a sample, such as a human serum sample, is initially brought into contact with the first analytical element of the assay by mixing or other means of being brought into contact therewith. This step can include some manner of incubation. Binding will occur between binding partners found in the sample which are associated with specific binding partners included in the first analytical element of the assay. This first analytical element is thereafter washed in order to become free of the unbound molecules of original sample and any unbound materials. The remaining portion of the assay including the first analytical element with material bound thereto is thereafter contacted with subsequent analytical elements of the assay. Additional processing steps can be included possibly including further washing or separating.
These wash or separation steps may be accomplished many ways such as by washing a coated well, magnetic particle separations, column chromatography, density separation or other types of steps. Normally, heterogeneous assays are used when high sensitivity and high assay precision are required. To achieve the desired sensitivity and precision, the reaction elements can be added in extremely excessive quantities. These reaction elements must be removed before subsequent analytical or processing elements are introduced.
Two molecules that can bind with respect to one another due to their mutual shapes or biologic activities are often referred to as a binding pair. Such a binding pair are usually described as being specifically associated with one another. These molecules actually fit together or attach as does a lock and key. Examples of such molecules are antibodies and the associated antigen with which each antibody specifically reacts. Other examples of binding pairs include receptors and the related hormones, cytokines, transmitters etc., complementary strands of DNA and enzymes and their substrates.
Each of the molecules that make up a binding pair are described as a binding partner. For example, an antibody not yet attached to its specific antigen is a binding partner and the specific antigen not yet attached is also defined as a binding partner. Another example of a binding partner includes single stranded DNA not hybridized to its complementary sequence.
2. Description of the Prior Art
Many compositions and methods have been patented for assaying for the purpose of determining the presence and quantity of a substance within a sample. Many of these patents are for the purpose of determining the presence of specific molecules such as antibodies within human serum samples.
The calibration of such assays has heretofore been deemed extremely difficult, especially for those assays which are homogeneous. The present invention provides a unique method for providing a dynamic and continuous calibration process for each individual human serum sample being tested wherein the calibration occurs at approximately the same time as the basic assay analysis. Also a customized calibration is provided for each distinct sample being analyzed rather than one single calibration for a multiplicity of sample tests that may be completely separate and distinct from one another except for the fact they may be testing in the same multi-well diagnostic tray.
Many patents have been granted for detecting and quantitatively measuring analytes in homogeneous and/or heterogeneous assays such as U.S. Pat. No. 4,493,899 patented Jan. 15, 1985 to L. Smith et al and assigned to City of Hope on a “Method Of Testing For Particular Antibodies In The Serum Of A Patient”; and U.S. Pat. No. 4,690,905 patented Sep. 1, 1987 to B. Diamond and assigned to Albert Einstein College of Medicine of Yeshiva University, a division of Yeshiva University on a “Method For Removal of Human Antibodies to Native DNA From Serum”; and U.S. Reissue Pat. No. Re. 32,696 patented Jun. 14, 1988 to A. Schuurs et al and assigned to Akzona Incorporated on an “Enzymatic Immunological Method For Determination Of Antigens And Antibodies”; and U.S. Pat. No. 4,868,104 patented Sep. 19, 1989 to N. Kurn et al and assigned to Syntex (U.S.A.) Inc. on a “Homogeneous Assay For Specific Polynucleotides”; and U.S. Pat. No. 5,028,545 patented Jul. 2, 1991 to E. Soiki and assigned to Wallac O Y on a “Biospecific Multianalyte Assay Method”; and U.S. Pat. No. 5,104,791 patented Apr. 14, 1992 to S. Abbott et al and assigned to E.I. Du Pont de Nemours and Company on “Particle Counting Nucleic Acid Hybridization Assays”; and U.S. Pat. No. 5,443,952 patented Aug. 22, 1995 to A. Pestronk and assigned to Washington University on “Autoantibodies And Their Targets In The Diagnosis Of Peripheral Neuropathies”; and U.S. Pat. No. 5,484,703 patented Jan. 16, 1996 to N. Raben et al and assigned to United States of America on an “Assay Using Recombinant Histidyl-Trna Synthetase”; and U.S. Pat. No. 5,567,627 patented Oct. 22, 1996 to B. Lehnen and assigned to Trans-Med Biotech, Incorporated on a “Method And Composition For The Simultaneous And Discrete Analysis of Multiple Analytes”; and U.S. Pat. No. 5,573,911 patented Nov. 12, 1996 to J. Victor et al and assigned to Lifecodes Corp. on “Methods And Materials For Detecting Autoimmune Antibodies”; and U.S. Pat. No. 5,599,538 patented Feb. 4, 1997 to S. Paul et al and assigned to Igen, Inc. on “Autoantibodies Which Enhance The Rate Of A Chemical Reaction”; and U.S. Pat. No. 5,663,066 patented Sep. 2, 1997 to N. Raben et al and assigned to The United States of America as represented by the Department of Health and Human Services and National Institutes of Health on an “Assay Using Recombinant Histidyl-Trna Synthetase”; and U.S. Pat. No. 5,736,330 patented Apr. 7, 1998 to R. Fulton and assigned to Luminex Corporation on a “Method And Compositions For Flow Cytometric Determination Of DNA Sequences”; and U.S. Pat. No. 5,776,487 patented Jul. 7, 1998 to N. Wilson et al and assigned to Pasteur Sanofi Diagnostics on “Liposome Reagents For Immunoassays”; and U.S. Pat. No. 5,780,319 patented Jul. 14, 1998 to N. Wilson et al and assigned to Pasteur Sanofi Diagnostics on “Immunoassays To Detect Antiphospnolipid Antibodies”; and U.S. Pat. No. 5,981,180 patented Nov. 9, 1999 to V. Chandler et al and assigned to Luminex Corporation on “Multiplexed Analysis Of Clinical Specimens Apparatus And Methods”; and U.S. Pat. No. 6,057,107 patented May 2, 2000 to R. Fulton and assigned to Luminex Corporation on “Methods And Compositions For Flow Cytometric Determination Of DNA Sequences”; and U.S. Pat. No. 6,107,047 patented Aug. 22, 2000 to C. Fledlius et al and assigned to Osteometer Biotech A/S on “Assaying Protein Fragments In Body Fluids”; and U.S. Pat. No. 6,117,646 patented Sep. 12, 2000 to P. Qvist et al and assigned to Osteometer Biotech A/S on “Assaying Protein Fragments In Body Fluids”; and U.S. Pat. No. 6,121,004 patented Sep. 19, 2000 to A. Pestronk and assigned to Washington University on “Autoantibodies And Their Targets In The Diagnosis Of Peripheral Neuropathies”; and U.S. Pat. No. 6,127,113 patented Oct. 3, 2000 to R. Atkinson et al and assigned to Obetech, LLC on “Viral Obesity Methods And Compositions”; and U.S. Pat. No. 6,150,113 patented Nov. 21, 2000 to R. Decker et al and assigned to Abbott Laboratories on a “Method For Increasing Specificity In Competitive Immunoassays”; and U.S. Pat. No. 6,156,179 patented Dec. 5, 2000 to S Binder et al and assigned to Bio-Rad Laboratories on “Computer Directed Identification Of Paraproteins”; and U.S. Pat. No. 6,159,699 patented Dec. 12, 2000 to R. Brown et al and assigned to Molecular Light Technology Limited on an “Enzyme Linked Chemiluminescent Assay”; and U.S. Pat. No. 6,159,748 patented to M. Hechinger on Dec. 12, 2000 and assigned to AffiniTech, LTD on an “Evaluation Of Autoimmune Diseases Using A Multiple Parameter Latex Bead Suspension And Flow Cytometry”; and U.S. Pat. No. 6,172,197 patented Jan. 9, 2001 to J. McCafferty et al and assigned to Medical Research Council and Cambridge Antibody Technology Limited on “Methods For Producing Members Of Specific Binding Pairs”.
3. Definitions    Ag=Antigen, a material to which an antibody binds.    DNA or dsDNA=Deoxyribose Nucleic Acid, dsDNA represents double stranded DNA    ELISA=Enzyme Linked Immunosorbent Assay. An assay where a binding partner, such as an antibody, is coupled to an enzyme. The presence of antibody binding is detected by adding a substrate that, if present, is acted on by the attached enzyme and creates a detectable change in the substrate.    IFA=Immunofluorescent assay or Indirect Fluorescent Assay. An assay where a binding partner is coupled to a fluorescent compound. The presence of binding by the binding partner is detected by a heterogeneous process including washing out of unbound material, and then looking for fluorescent staining of a solid substrate such as cell or tissue section microscopically using a immunofluorescent microscope.    IgG=Immunoglobulin G. One of several classes of immunoglobulins or antibodies.    mL=Milliliter.    mg=milligram    PE=Phycoerythrin, a fluorescent phycobilliproten that may be used as a reporter molecule.    SLE=Systemic Lupus Erythematosis. A systemic autoimmune disease characterized by the presence of antibodies to “self” components such as DNA.